get_url fails to find images when cachebust=true

[videah]

Bug Report

Environment

Zola version: zola 0.17.1

Expected Behavior

get_url should return a cachebusting URL to an image as it did in 0.16

Current Behavior

Builds will fail saying get_url can't find or open the image file. This seems to only apply to image files, text files like .js will work just fine. This has only started happening as of 0.17 and was not an issue with 0.16.

Step to reproduce

1. Run zola init and use default config
2. Put two images called test1.png and test2.png along with a text file called test.js in static
3. Create an index.html in templates with the following content:

<!-- This finds this text file no problem, even with cachebust on -->
<script src="{{ get_url(path='test.js', cachebust=true) }}"></script>

<!-- This will find test1.png successfully -->
<img src="{{ get_url(path='test1.png') }}"/>

<!-- This will fail to find test2.png  -->
<img src="{{ get_url(path='test2.png', cachebust=true) }}"/>

4. Run zola build

zola build
Building site...
Checking all internal links with anchors.
> Successfully checked 0 internal link(s) with anchors.
-> Creating 0 pages (0 orphan) and 0 sections
Error: Failed to build the site
Error: Failed to render section '/Users/videah/Git/zola-bug/content/_index.md'
Error: Reason: Failed to render 'index.html'
Error: Reason: Function call 'get_url' failed
Error: Reason: `get_url`: Could not find or open file test2.png

[Keats]

It should be fixed in the next branch